III.A.3 Pair Production. Another agent is optical illumination. These holes are not produced by the addition of the pentavalent impurity atoms. Related electrical process: electron - hole pair recombination When the excited electron meets the hole in the valence band, it may occupy that place. These pairs are the constituents of electricity. In the semiconductor, free charge carriers are electrons and electron holes (electron-hole pairs). An electron hole is one of the two types of charge carriers that are responsible for creating electric current in semiconducting materials.A hole can be seen as the "opposite" of an electron.Unlike an electron which has a negative charge, holes have a positive charge that is equal in magnitude but opposite in polarity to the charge an electron has. Electron-hole pairs are produced by (a) recombination (b) thermal energy (c) ionization (d) doping. Both carriers eventually disappear in the process. This electron is free for conduction about the crystal lattice. Thermal energy is one of the agents which causes pair generation. View Answer: Answer: Option B. The electrons are called the majority carriers in n-type material. (a) An intrinsic semiconductor is an insulator having a complete electron shell. Other articles where Electron-hole pair is discussed: materials science: Photovoltaics: The electron motion, and the movement of holes in the opposite direction, constitute an electric current. As electron and hole are produced simultaneously, the process is called electron-hole pair generation. As a result the e-h pair disappear; this process is called recombination. (b) However, thermal energy can create few electron-hole pairs resulting in weak conduction. The free electron (negative charge) and the hole (positive charge) are a pair. An electron hole (often simply called a hole) is the lack of an electron at a position where one could exist in an atom or atomic lattice. If the energy released through recombination is in the form of a photon, the process is known as radiative-recombination and is most common for electrons moving fully from the conduction to the valence band. J.Gregory Stacy, W.Thomas Vestrand, in Encyclopedia of Physical Science and Technology (Third Edition), 2003. n i is produced by a dynamic process; free electron hole pairs are continually being generated, while other electron hole pairs are recombining In the process of generation, a covalent bond is broken and a bound electron is transformed into a free electron. Recombination of electrons and holes is a process by which both carriers annihilate each other: electrons occupy - through one or multiple steps - the empty state associated with a hole. In the pair production process, an incident gamma ray of sufficiently high energy is annihilated in the Coulomb field of a nearby charged particle, resulting in the creation of an electron–positron pair. During recombination, the electron energy is released as a photon with the energy closed to the bandgap energy of the Thermal energy may occasionally free an electron from the crystal lattice as in Figure above (b). Solution: 15. Electrons and holes are created by excitation of electron from valence band to the conduction band. Answer to Electron-hole pairs are produced by(a) recombination(b) thermal energy(c) ionization(d) doping. free-electron concentration is equal to hole concentration (whole pure Si crystal is charge neutral), and either one is represented by the symbol n i, which is called the intrinsic carrier concentration. Although the majority of current carriers in n-type material are electrons, there are also a few holes that are created when electron-hole pairs are thermally generated. The process of electron and hole annihilation is known as recombination. The result of light of sufficient energy dislodging an electron from its bond in a crystal, which creates a hole. 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